1. Field of the Invention
The present invention generally relates to the field of telecommunications and to an apparatus and method for managing telephony-based services, such as routing and translations services. More particularly, the present invention relates to an intelligent or advanced application, such as an Advanced Intelligent Network (AIN) application, for routing a special or dedicated identifier through multiple paths out of an AIN end office to a dedicated or special purpose telecommunications system, such as the Government Emergency Telecommunications Service (GETS).
2. Acronyms
The written description provided herein contains acronyms which refer to various communication services and system components. Although known, use of several of these acronyms is not strictly standardized in the art. For purposes of the written description herein, acronyms will be defined as follows:
10D—10 Digit Trigger
AIN—Advanced Intelligent Network
ACR—Alternate Carrier Routing
CCIS—Common Channel Interoffice Signaling
CCS—Common Channel Signaling
CO—Central Office
CIC—Carrier Identification Code
CPR—Call Processing Record
CPN—Calling Party Number
DID—Direct Inward Dialing
DLN—Dialed Line Number
DRS—Data and Reports System
EO—End Office
FIM—Feature Interaction Manager
ISCP—Integrated Service Control Point
ISUP—ISDN User Part
IXC—Interexchange Carrier
LATA—Local Access and Transport Area
MF—Multi-Frequency
NANP—North American Numbering Plan
NPA—Numbering Plan Area
NXX—Central Office Code
PIC—Primary Interexchange Carrier
PRI—Primary Rate Interface
PSTN—Public Switched Telephone Network
SCE—Service Creation Environment
SCP—Service Control Point
SMS—Service Management System
SRAS—Special Routing Access Service
SS7—Signaling System 7
SSP—Service Switching Point
STP—Signaling Transfer Point
TAT—Termination Attempt Trigger
TCAP—Transaction Capabilities Applications Part
TG—Trunk Group
TN—Telephone Number
3. Background Information
(a) Government Emergency Telecommunications Service (GETS)
GETS is a telecommunications system maintained by GTE and the federal government for use during emergencies. Specifically, the Numbering Plan Area (NPA) code of 710 was established for the special federal government telephone number 710-NCS-GETS (i.e., 710-627-4387). In the prior art, this telephone number was routed to GETS either through the Primary Interexchange Carrier (PIC) of the calling location for offices with a GETS service, or through AT&T for a calling location that has contracted with AT&T for Special Routing Access Service (SRAS).
A drawback of the above arrangement is that only a single telephone carrier is available for connecting any one node/office to GETS. However, during an emergency, the particular carrier may not be available and/or accessible. For example, a flood of calls to a disaster area, downed communication lines, or damage to the carrier itself may cause service outage or overload.
(b) Advanced Intelligent Networks
In recent years, Advanced Intelligent Networks (AIN) have provided a number of new telephone service features. The AIN evolved out of a need to increase the capabilities of the telephone network architecture to meet the growing needs of telephone customers or users. The AIN architecture generally comprises two networks, a data messaging network and a trunked communications network. The trunked communications network handles voice and data communications between dispersed network locations, whereas the data messaging network is provided for controlling operations of the trunked communications network.
An illustration of the basic components of AIN architecture is shown in FIG. 1. As shown in FIG. 1, Service Switching Points (SSP's) 64-70 are provided for sending and receiving data messages from a Service Control Point (SCP) 56 via Signaling Transfer Points (STP's) 58-62. The data messages are communicated to and from the SSP's 64-70 and the SCP 56 along a Common Channel Signaling (CCS) network 88. Each SSP 64-70 routes telephone calls between a plurality of dispersed network stations 172-186. For example, SSP's 64-70 may route a telephone call between a calling station (e.g., station 172) and a called station (e.g., station 184) through trunks 90 and customer lines 92 (e.g., telephone lines). Stations 172-186 may comprise various customer or terminal equipment, such as a telephone unit (wired, cellular or mobile), a facsimile machine, and/or a modem attached to a personal computer.
More information regarding AIN may be found in various publications. See, for example, Berman, Roger K., and Brewster, John H., “Perspectives on the AIN Architecture,” IEEE Communications Magazine, February 1992, pp. 27-32, the disclosure of which is expressly incorporated herein by reference in its entirety.
A number of services or features provided by prior AIN or AIN-type intelligent networks relate to specialized call processing or recording of incoming calls and call traffic. For example, U.S. Pat. No. 5,583,926 discloses routing of calls to dedicated numbers. The subscriber can select an overflow routing option to provide a list of overflow routes or trunks to provide alternate routes within a single network to connect a call. The alternate routes may be available to the Primary Interexchange Carrier if the most direct route is overloaded.
A drawback of the above-noted patent is that while it establishes several routes to place calls to a carrier, it cannot route the call to an alternate carrier if the carrier is disabled or otherwise inaccessible. Further, prior systems do not permit a user or party to dial a dedicated number to optionally select a specific carrier and/or backup carriers to ensure completion of the call.